Cyclooct-(en-)yl derivatives for use as fragrances

ABSTRACT

This invention relates to substituted cyclooctenes of the formula I, wherein X and R are defined in the specification.

This invention relates to substituted cyclooctenes having agrestic,natural, and floral, green, woody odour notes, their manufacture, and tofragrance compositions containing them.

Substituted cyclooctenes have been described in the literature, forexample, the German patent publication DE 19814913 A1 disclosescyclooctene aldehydes, such as cyclooct-4-en aldehyde (1) possessing anodour note described to be comparable with the odour of fresh harvestedpotatoes.

Whereas the odour notes imparted by cyclooct-4-en aldehyde (1) may beinteresting in their own right, in the fragrance industry, there isalways an ongoing demand for new compounds that enhance or improve onodour notes, or impart new odour notes.

Surprisingly, we have now found certain monosubstituted cyclooctenesstructurally similar to (1), but which possess characteristicallydifferent odour notes which are described as agrestic and thujone-like,and floral, green, woody odour notes.

In a first aspect, the invention refers to the use of a compound offormula I as fragrance,

wherein X is carbonyl, or —(CHOH)—; and

R is methyl or ethyl, or linear or branched C₃ to C₅ alkyl, such asi-propyl, n-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl,sec-pentyl, and tert-pentyl; or

R is vinyl, or linear or branched C₃ to C₅ alkenyl, such as propen-1-yl,propen-2-yl, allyl, but-1-en-1-yl, but-2-en-1-yl, but-3-en-1-yl, andpentenyl; and

the dotted line represents one optional double bond.

The compounds according to the present invention may contain one or morechiral centres and as such may exist as a mixture of stereoisomers, orthey may be resolved as isomerically pure forms. Resolving stereoisomersadds to the complexity of manufacture and purification of thesecompounds and so it is preferred to use the compounds as mixtures oftheir stereoisomers simply for economic reasons. However, if it isdesired to prepare individual stereoisomers, this may be achievedaccording to methodology known in the art, e.g. preparative HPLC and GCor by stereoselective syntheses.

Preferred compounds of formula I are 1-cyclooct-3-enylethanone,1-cyclooct-3-enylpropan-1-one,1-cyclooct-3-enyl-2-methylpropan-1-one,1-cyclooct-3-enylpropan-1-ol,1-cyclooct-4-enylethanone, 1-cyclooct-2-enylethanone,1-cyclooct-2-enylethanol, 1-cyclooct-1-enylethanone,1-cyclooctylpropanone, 1-cyclooctyl-2-methylpropanone, and1-cyclooctyl-2-methylpropanol.

Particularly preferred are compounds of formula I having a double bondat position C-3, i.e. a compound of formula I wherein the bond betweenC-3 and C-4 together with the dotted line represents a double bond, andthe bonds between C-1 and C-2, C-2 and C-3, and C-4 and C-5 representeach a single bond, such as 1-cyclooct-3-enylethanone,1-cyclooct-3-enylpropan-1-one, 1-cyclooct-3-enyl-2-methylpropan-1-oneand 1-cyclooct-3-enylpropan-1-ol.

As used in relation to compounds of formula I “one optional double bond”refers to compounds of formula I wherein the bond between C-1 and C-2together with the dotted line represents a double bond, and the bondsbetween C-2 and C-3, C-3 and C-4, and C-4 and C-5 represent each asingle bond; or the bond between C-2 and C-3 together with the dottedline represents a double bond, and the bonds between C-1 and C-2, C-3and C-4, and C-4 and C-5 represent each a single bond; or the bondbetween C-3 and C-4 together with the dotted line represents a doublebond, and the bonds between C-1 and C-2, C-2 and C-3, and C-4 and C-5represent each a single bond; or

the bond between C-4 and C-5 together with the dotted line represents adouble bond, and the bonds between C-1 and C-2, C-2 and C-3, and C-3 andC-4 represent each a single bond; or the bonds between C-1 and C-2, C-2and C-3, C-3 and C-4, and C-4 and C-5 represent each a single bond.

The compounds according to the present invention may be used alone or incombination with known odourant molecules selected from the extensiverange of natural products and synthetic molecules currently available,such as essential oils, alcohols, aldehydes and ketones, ethers andacetals, esters and lactones, macrocycles and heterocycles, and/or inadmixture with one or more ingredients or excipients conventionally usedin conjunction with odourants in fragrance compositions, for example,carrier materials, and other auxiliary agents commonly used in the art.

The following list comprises examples of known odourant molecules, whichmay be combined with the compounds of the present invention:

natural products: tree moss absolute, basil oil, tropical fruit oils(such as bergamot oil, mandarin oil, etc.), mastix absolute, myrtle oil,palmarosa oil, patchouli oil, petitgrain oil, wormwood oil, lavenderoil, rose oil, jasmin oil, ylang-ylang oil.

alcohols: farnesol, geraniol, linalool, nerol, phenylethyl alcohol,rhodinol, cinnamic alcohol, (Z)-hex-3-en-1-ol, menthol, α-terpineol.

aldehydes: citral, α-hexyl cinnamaldehyde, Lilial, methylionone,verbenone, nootkatone, geranylacetone.

esters: allyl phenoxyacetate, benzyl salicylate, cinnamyl propionate,citronellyl acetate, decyl acetate, dimethylbenzylcarbinyl acetate,dimethylbenzylcarbinyl butyrate, ethyl acetoacetate, cis-3-hexenylisobutyrate, cis-3-hexenyl salicylate, linalyl acetate, methyldihydrojasmonate, styralyl propionate, vetiveryl acetate, benzylacetate, geranyl acetate.

lactones: γ-undecalactone, δ-decalactone, pentadecanolide,12-oxahexadecanolide.

acetals: Viridine (phenylacetaldehyde dimethylacetal).

other components often used in perfumery: indole,p-mentha-8-thiol-3-one, methyleugenol, eugenol, anethol.

Whereas a single compound of formula I enhances, or improves on odournotes in their own right, it was found that a mixture of double bondisomers enhances the diffusion of a fragrance even more. Thus, thepresent invention refers in a further aspect to a fragrance compositioncomprising a mixture of A) a compound of formula Ic; and B) at least onecompound selected from a compound of formula Ia, a compound of formulaIb, and a compound of formula Id

wherein X and R have the same meaning as defined above and R═R′═R″═R″′and X═X′═X″═X′″.

Particularly preferred are mixtures comprising a compound of formula Ia,a compound of formula Ic, and a compound of formula Id. Preferredmixtures are those comprising at least 50% by weight of a compound offormula Ic based on the total weight of all double bond isomers, i.e.amount of the compound of formula Ia+Ib+Ic+Id=100% by weight.

The compounds of the present invention may be used in a broad range offragrance applications, e.g. in any field of fine and functionalperfumery. The compounds can be employed in wide ranging amountsdepending upon the specific application and on the nature and quantityof other odourant ingredients, that may be for example, from about 0.001to about 20 weight percent of the application. In one embodiment,compounds may be employed in a fabric softener in an amount of about0.001 to 0.05 weight percent. In another embodiment, compounds of thepresent invention may be used in an alcoholic solution in amounts ofabout 0.1 to 20 weight percent, more preferably between about 0.1 and 5weight percent. However, these values should not be regarded as limitingthe present invention, since the experienced perfumer may also achieveeffects or may create novel accords with lower or higher concentrations.

The compounds of the present invention may be employed into thefragrance application simply by direct mixing the compound of thepresent invention or the fragrance composition comprising the compoundwith the fragrance application. Alternatively, they may be added in anentrapped form, by being in a previous step entrapped with an entrapmentmaterial, for example polymers, capsules, microcapsules andnanocapsules, liposomes, precursors, film formers, absorbents, forexample by using carbon or zeolites, cyclic oligosaccharides andmixtures thereof, and then mixed with the application.

Thus, the invention additionally provides a method of manufacturing afragrance application, comprising the incorporation of a compound offormula I as a fragrance ingredient, either by directly admixing thecompound of formula I into the application or by admixing a fragrancecomposition comprising a compound of formula I, which may then be mixedto a fragrance application, using conventional techniques and methods.

As used herein, “fragrance application” means any product, such as fineperfumery, e.g. perfume and Eau de Toilette; household products, e.g.detergents for dishwasher, surface cleaner; laundry products, e.g.softener, bleach, detergent; body care products, e.g. shampoo, showergel; and cosmetics, e.g. deodorant, vanishing creme, comprising anodourant. This list of products is given by way of illustration and isnot to be regarded as being in any way limiting.

Whereas some compounds have been described in the literature, othershave not, and are novel. Thus, in another aspect of the invention, thereis provided a compound of formula I

wherein X is carbonyl, or —(CHOH)—; and

R is methyl or ethyl, or linear or branched C₃ to C₅ alkyl, such asi-propyl, n-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl,sec-pentyl, and tert-pentyl; or

R is vinyl or linear or branched C₃ to C₅ alkenyl, such as propen-1-yl,propen-2-yl, allyl, but-1-en-1-yl, but-2-en-1-yl, but-3-en-1-yl, andpentenyl; and

the dotted line represents one optional double bond;

provided that

when X is carbonyl and one of the bonds between C-1 and C-2, C-2 andC-3, and C-3 and C-4 together with the dotted line is a double bond, Ris not methyl or ethyl;

when X is carbonyl and the bond between C-2 and C-3 together with thedotted line is a double bond, R is not i-propyl;

when X is carbonyl and the bond between C-3 and C-4 together with thedotted line is a double bond, R is not methyl or ethyl;

when X is carbonyl and all of the bonds between C-1 and C-2, C-2 andC-3, C-3 and C-4, and C-4 and C-5 together with the dotted linerepresent each a single bond, R is not methyl or ethyl;

when X is —(CHOH)—, R is not methyl; and

when X is —(CHOH)— and the bond between C-2 and C-3 together with thedotted line is a double bond, R is not ethyl.

Compounds of formula I, wherein the bond between C-3 and C-4 togetherwith the dotted line represents a double bond, i.e. substitutedcyclooct-3-enes, may be prepared by the reaction of olefins with anappropriately substituted carboxylic acid, well known to a personskilled in the art and described for example by Schellhammer (Methodender Organischen Chemie (Houben-Weyl), 1973, Band VII/2a, pages 447 -460)herein incorporated by reference, starting from cyclooctene by acylationwith the appropriately substituted carboxylic acid. The resultingketones (2) may be reduced to give further compounds of formula I asshown in scheme 1.

Compounds of formula I, wherein the bond between C-2 and C-3 togetherwith the dotted line represents a double bond, i.e. substitutedcyclooct-2-enes, may be prepared by selective bromination ofcyclooctene, resulting in 3-bromo-cyclooctene, followed by addition ofthe appropriate aldehyde R—CHO under Grignard type reaction conditionsknown to the person skilled in the art. The resulting alcohols (3) maybe oxidised to give further compounds of formula I as shown in scheme 2.

Compounds of formula I wherein the bond between C-4 and C-5 togetherwith the dotted line represents a double bond, i.e. substitutedcyclooct-4-enes, may be prepared by selective bromination under acidicconditions starting from cycloocta-1,5-diene, resulting in5-bromo-cyclooctene, followed by addition of the appropriate aldehydeunder Grignard conditions, resulting in an alcohol which may be oxidisedto give further compounds of formula I.

Compounds of formula I wherein the bond between C-1 and C-2 togetherwith the dotted line represents a double bond, i.e. substitutedcyclooct-1-enes, may be prepared by the reaction of the appropriatealkynes with cyclooctanone under alkaline conditions, followed by Ruperearrangement under acidic conditions.

Alternatively, a double bond isomeric mixture of compounds of formula I,i.e. a mixture of substituted cyclooct-1-enes, -3-enes and 4-enes, maybe prepared by addition of an alkanoic acid chloride to cyclooctenefollowed by dehydrochlorination of the resulting chloro-cyclootylalkanone under conditions known to the person skilled in the art.

Further particulars as to reaction conditions are provided in theexamples.

There now follows a series of non-limiting examples that illustrate theinvention.

EXAMPLE 1 1-cyclooct-3-enylethanone

To cyclooctene (300 g, 2.73 mol) were added acetic anhydride (556 g,5.45 mol) and zinc chloride (30 g, 0.22 mol). The reaction mixture waswarmed to 90-95° C. within 30 min., stirred at that temperature during7.5 hours, cooled to 60° C., and treated with caution, within 10 min.,with water (400 ml). The resulting mixture was heated at 100° C. during3 h., cooled to 25° C., and extracted with hexane (3×300 ml). Thecombined organic phases were washed with aq. sat. NaCl soln. (800 ml),aq. sat. NaHCO₃ soln. (800 ml), aq. sat. NaCl soln. (400 ml), and dried(Na₂SO₄). Evaporation of the solvent led to 375 g of crude materialwhich was distilled under vacuum with a short-path Vigreux column. Aftercollecting the unreacted cyclooctene (65 g, 21.7%) at 40-50° C./100mbar, the fractions distilling at 110° C./24 mbar were collected (144 g)and redistilled using a microdistillation column (20×1.5 cm, filled with3×3 mm rolled wire netting) to give 110 g of 1-cyclooct-3-enylethanone(34% based on the reacted cyclooctene, 109° C./20 mbar) as colourlessoil.

¹H-NMR (400 MHz, CDCl₃): δ1.40-1.85 (m, 6H), 2.05-2.16 (m, 1H), 2.16 (s,Me), 2.16-2.30 (m, 2H), 2.38-2.47 (m, H—C(2)), 2.49-2.57 (m, H—C(1)),5.60 (dd, J=8.2, 18.5, H—C(3)), 5.73 (dd, J=8.0, 18.3, H—C(4)). ¹³C-NMR(100 MHz, CDCl₃): δ24.19 (t, C(7)), 25.58 (t, C(5)), 26.13 (t, C(2)),27.12 (t, C(8)), 28.08 (q, Me), 28.96 (t, C(6)), 52.66 (d, C(1)), 127.38(d, C(3)), 131.48 (d, C(4)), 211.20 (s, CO). MS (El): 152 (15), 137 (7),134 (15), 119 (10), 109 (35), 94 (21), 79 (36), 67 (100), 55 (37), 43(100). IR: v_(max) 3016, 2927, 2855, 1708, 1666, 1466, 1467, 1352, 1241,1165, 1120, 959, 755, 706 cm⁻¹.

Odour description: agrestic, armoise, wormwood, thujone, natural.

EXAMPLE 2 1-cyclooct-3-enylpropan-1-one

Obtained according to the experimental procedure of Example 1 fromcyclooctene (150 g, 1.36 mol), propionic anhydride (354 g, 2.72 mol) andzinc bromide (30.6 g, 0.14 mol) in 27% yield. Boiling point 60° C./80mbar.

¹H-NMR (400 MHz, CDCl₃): δ1.04 (t, J=7.3, Me), 1.40-1.80 (m, 6H),2.03-2.12 (m, 1H), 2.17-2.27 (m, 2H), 2.39-2.58 (m, H—C(2), CH₂CO,H—C(1)), 5.60 (dd, J=8.1, 18.5, H—C(3)), 5.73 (dd, J=8.4, 18.4, H—C(4)).MS (El): 166 (18), 137 (16), 109 (41), 94 (19), 79 (25), 67 (100), 57(83), 41 (34), 29 (39). IR: v_(max) 3017, 2928, 2855, 1708, 1669, 1464,1413, 1375, 1115, 973, 754, 705 cm⁻¹.

Odour description: fruity, banana, tagete.

EXAMPLE 3 1-cyclooct-3-enyl-2-methylpropan-1-one

Obtained according to the synthetic procedure of Example 1 fromcyclooctene (150 g, 1.36 mol), isobutyric anhydride (430.3 g, 2.72 mol)and zinc bromide (30.6 g, 0.14 mol) in 33% yield. Boiling point 85°C./80 mbar).

¹H-NMR (400 MHz, CDCl₃): δ1.08 (t, J=7.0, Me), 1.39-1.78 (m, 6H),2.02-2.29 (m, 3H), 2.42 (dt, J=8.8, 13.6, H—C(2)), 2.62-2.70 (m,H—C(1)), 2.79 (h, J=6.9, H—C Me₂), 5.60 (dd, J=8.4, 18.4, H—C(3)), 5.74(dd, J=8.0, 18.4, H—C(4)). MS (El): 180 (17), 165 (1), 137 (21), 119(6), 109 (59), 94 (9), 81 (13), 79 (14), 71 (32), 67 (100), 55 (29), 53(10), 43 (63), 39 (20), 27 (14). IR: v_(max) 3017, 2967, 2928, 2857,1701, 1666, 1466, 1382, 1051, 1004, 756, 735 cm⁻¹.

Odour description: fruity, green.

EXAMPLE 4 1-cyclooct-3-enylpropan-1-ol

1-cyclooct-3-enylpropan-1-one (84.0 g, 0.5 mol) was slowly added to asolution of sodium borohydride (11.9 g, 0.3 mol) in ethanol (330 ml) at0° C. (ice bath), and stirring was continued at room temperature for 4h. The reaction mixture was poured into ice-cold 2N HCl (500 ml) andextracted with MTBE (2×200 ml). After washing with brine (3×200 ml),drying (MgSO₄) and evaporation of solvents, the yellowish oily residue(86.6 g) was distilled over a 20 cm

Widmer column (66-80° C./0.7-0.8 mbar) to give 69.2 g of1-cyclooct-3-enylpropan-1-ol (colourless oil, 68% yield). It consistedof >90% of a 1:1 mixture of two diastereomeric racemates of1-cyclooct-3-enylpropan-1-ol. An analytical sample was purified by flashchromatography (hexane/MTBE 3:1).

R_(f) 0.51. ¹H-NMR (200 MHz, CDCl₃): δ0.95 and 0.97 (2t, J=7.4 and 7.3,3H), 1.22-1.76 (m, 10H), 2.02-2.27 (m, 4H), 3.32-3.46 (m, 1H), 5.54-5.70(m, 2H). ¹³C-NMR: diast. rac. A: δ10.1 (q), 24.6 (t), 25.4 (t), 26.4(t), 27.1 (t), 28.5 (t) 29.1 (t), 45.2 (d), 77.1 (d), 128.9 (d), 130.4(d); diast. rac. B: δ10.2 (q), 24.2 (t), 25.3 (t), 26.8 (t), 26.9 (t),27.8 (t), 28.9 (t), 45.2 (d), 77.1 (d), 128.9 (d), 130.3 (d). MS (El):168 (M⁺,2), 150(16), 139(16), 121(76), 109(25), 107(26), 93(31), 82(28),81(35), 79(49), 67(100), 59(50), 57(41), 55(43), 41(55). IR (neat):v_(max) 3359, 2925, 2856, 1466, 1106, 968, 755, 705 cm⁻¹.

Odour description: cassie, mimosa, green, moss, natural, forest, fatty

EXAMPLE 5 1-Cyclooct-4-enylethanone

A solution of 5-bromo-cyclooctene (5 g, 26 mmol; prepared by treatmentof 1,5-cyclooctadiene with HBr in AcOH) in diethyl ether was added tomagnesium (0.7 g, 29 mmol, 1.1 eq.). The resulting solution was cooledto 5° C. and treated dropwise with a solution of acetaldehyde (5 ml, 89mmol, 3.4 eq.) in diethyl ether (10 ml). The resulting mixture wasstirred 3 h at 20° C., treated with 2M HCl, and extracted with diethylether. The organic phases were washed successively with NaHCO₃, NH₄Cland NaCl solutions, and dried (Na₂SO₄) and the solvent evaporated undervacuum. The crude product was purified by flash chromatography(hexane/Et₂O 10:1) to give 1.2 g of 1-cyclooct-4-enylethanone (30%).

¹³C-NMR (100 MHz, CDCl₃): δ24.18 (t), 25.79 (t), 27.87 (q), 27.99 (t),28.16 (t), 30.53 (t), 51.58 (d, C(1)), 129.65 (d), 130.53 (d), 212.28(s). MS (El): 152 (1), 137 (7), 134 (30), 119 (14), 109 (27), 105 (7),94 (14), 79 (34), 67 (77), 55 (28), 43 (100), 39 (31).

Odour description: green leaves, thuja oil, armoise, fruity.

EXAMPLE 6 1-Cyclooct-2-enylethanol and 1-cyclooct-2-enylethanone

At −50° C., a solution of 3-bromo-cyclooctene (4.2 g, 22 mmol; preparedby reaction of cyclooctene with N-bromosuccinimide) andtitanium(IV)isopropoxide (7.2 ml, 24 mmol, 1.1 eq.) in diethyl ether(100 ml) was treated with a 2M solution of isopropylmagnesium chloridein diethyl ether (49 mmol, 2.2 eq.). The resulting mixture was stirred1.5 h at −50° C., treated with acetaldehyde (1 ml, 18 mmol, 0.8 eq.),stirred 1 h at −40° C., and treated with 2M aqueous HCl solution. Afterextraction with MTBE (2×100 ml), washing of the organic phases withwater (2×200 ml) and aqueous NaCl solution (200 ml), and drying (MgSO₄),the crude product (4.4 g) was purified by flash chromatography(hexane/MTBE 6:1) to give 0.7 g of 1-cyclooct-2-enylethanol (26%).

¹³C-NMR (100 MHz, CDCl₃): δ21.27 (q), 25.51 (t), 26.64 (t), 26.82 (t),29.38 (t), 31.78 (t), 43.83 (d), 71.44 (d, CHOH), 130.43 (d), 130.54(d). MS (El): 154 (1), 136 (1), 121 (2), 110 (48), 95 (25), 82 (100), 67(93), 54 (35), 45 (65), 41 (43).

Odour description: green, earthy, fruity, fresh

At 0° C., a solution of 1-cyclooct-2-enylethanol (1.4 g, 9 mmol) indichloromethane (20 ml) was added to pyridiniumchlorochromate (2.35 g,11 mmol) in dichloromethane (30 ml). The resulting mixture was stirredat 20° C. during 3.5 h and filtered through Celitee ®. The filtrate wasconcentrated and the crude product purified by flash chromatography(hexane/Et₂O 6:1) to give 0.7 g of 1-cyclooct-2-enylethanone (55%).

¹³C-NMR (100 MHz, CDCl₃): δ25.20 (t), 26.41 (t), 26.58 (t), 28.73 (q),29.14 (t), 31.77 (t), 50.38 (d), 127.40 (d), 131.83 (d), 210.52 (s, CO).MS (El): 152 (14), 137 (4), 134 (5), 124 (3), 110 (4), 109 (31), 95(18), 94 (10), 81 (20), 79 (21), 67 (98), 55 (29), 43 (100), 39 (22).

Odour description: green, thuja oil, wormwood, fruity.

EXAMPLE 7 1-Cyclooct-1-enylethanone

At 35° C., a solution of lithium acetylide-ethylene diamine (50 g, 0.49mol) in THF (500 ml) was slowly treated (reaction temperature≦35° C.)with a solution of cyclooctanone (51.4 g, 0.41 mol) in THF (100 ml). Theresulting mixture was stirred for 4 h at 20° C., 15 h at 45° C., cooledto 5° C., treated with aqueous sat. NH₄Cl solution (250 ml) and washedwith 3M aqueous HCl. After extraction with Et₂O, the organic phases werewashed with water, aqueous sat. Na₂CO₃ solution, dried (Na₂SO₄), andconcentrated to give 1-ethynylcyclooctanol (66.6 g). A solution of crude1-ethynylcyclooctanol (65 g) in formic acid (130 ml) was heated for 2.5h at 80° C. The resulting mixture was taken up in Et₂O and washedsuccessively with water, 5M NaOH, water, aqueous sat. NH₄Cl solution,dried (Na₂SO₄), and concentrated to give 56 g of crude product. Afraction (8 g) was purified by flash chromatography (hexane/Et₂O95:5→9:1) to give 4.1 g of 1-cyclooct-2-enylethanone.

MS (El): 152 (43), 137 (31), 123 (15), 109 (48), 81 (21), 67 (67), 55(23), 43 (100).

Odour description: fruity, sweet, anisic, minty, terpineol,camphoraceous.

EXAMPLE 8 1-Cyclooctylpropanone

A solution of 1-cyclooct-3-enylpropan-1-one (1.5 g, 9 mmol) in ethanol(20 ml) was treated with 10% palladium on charcoal (0.09 g) at roomtemperature and the resulting suspension was hydrogenated during 40 min.at 20 bars. After filtration through Celitee ® and concentration undervacuum, the crude product was purified by flash chromatography(hexane/Et₂O 19:1) to give 0.78 g of 1-cyclooctylpropanone (52%).

¹³C-NMR (100 MHz, CDCl₃): δ8.06 (q), 25.54 (t, 2 CH₂), 26.28 (t), 26.60(t, 2 CH₂), 28.16 (t, 2 CH₂), 33.95 (t), 50.47 (d), 215.15 (s, CO). MS(El): 168 (3), 139 (17), 111 (47), 69 (100), 55 (55), 41 (45), 29 (34).

Odour description: fruity, green.

EXAMPLE 9 1-Cyclooctylethanone

Obtained according to the synthetic procedure of Example 8 from of1-cyclooct-3-enylethanone in 49% yield. Boiling point 154° C./120 mbar.

¹³C-NMR (100 MHz, CDCl₃): δ25.47 (t, 2 CH₂), 26.24 (t), 26.60 (t, 2CH₂), 27.94 (t, 2 CH₂), 28.01 (q), 51.54 (d). MS (El): 154 (4), 139 (3),125 (6), 111 (18), 96 (19), 81 (10), 69 (100), 55 (58), 43 (66), 39(19).

Odour description: agrestic, camphoraceous, armoise, thujone-like,earthy, woody.

EXAMPLE 10 1-Cyclooctyl-2-methylpropanone

A solution of 1-cyclooct-3-enyl-2-methylpropanone (5.0 g, 28 mmol) inethanol (50 ml) was treated with 10% palladium on charcoal (0.2 g) atroom temperature and the resulting suspension was hydrogenated during 60min. at 20 bars. After filtration through Celitee ® and concentrationunder vacuum, the crude product was purified by flash chromatography(hexane/Et₂O 19:1) to give 0.9 g of 1-cyclooctyl-2-methylpropanone(43%).

¹³C-NMR (100 MHz, CDCl₃): δ18.59 (q, 2 Me), 25.56 (t, 2 CH₂), 26.34 (t),26.55 (t, 2 CH₂), 28.30 (t, 2 CH₂), 39.28 (d), 48.71 (d), 218.26 (s,CO). MS (El): 182 (5), 167 (1), 153 (1), 139 (16), 111 (66), 69 (100),55 (41), 43 (39), 41 (39).

Odour description: floral, fruity, balsamic.

EXAMPLE 11 1-Cyclooctyl-2-methylpropanol

A suspension of sodium borohydride (0.29 g, 8 mmol) in methanol (30 ml)was treated with a solution of 1-cyclooctyl-2-methylpropanone (2.0 g, 11mmol) in methanol (20 ml) at room temperature. The resulting mixture wasstirred at 20° C. during 20 h, poured over 2 M aqueous HCl (50 ml) andextracted with MTBE (2×80 ml). The organic phases were washed with water(100 ml), aqueous sat. NaCl solution (100 ml), and dried (MgSO₄). Thecrude product was purified by flash chromatography (hexane/Et₂O 7:1) togive 1.7 g of 1-cyclooctyl-2-methylpropanol (81%).

¹³C-NMR (100 MHz, CDCl₃): δ17.41 (q), 19.93 (q), 25.68 (t), 26.25 (t),26.34 (t), 26.68 (t), 26.77 (t), 27.03 (t), 30.32 (d), 31.12 (t), 39.25(d), 82.35 (d). MS (El): 183 (1), 166 (1), 141 (14), 123 (33), 110 (11),95 (12), 81 (59), 73 (100), 69 (31), 55 (63), 41 (41).

Odour description: floral, woody, rosy, fruity.

EXAMPLE 12 A fragrance Composition for a Soap

compound/ingredient parts by weight 1/1000 Civette GIVCO 208* 1 Ethylvanilline 1 cis-Jasmone 1 Castoreum GIVCO 116* 2 Galbanum GIVCO 121* 2Aldehyde C11 Undecylic 3 Cyclal C 3 Petitgrain essential oil Paraguay 3Iso Butyl Quinoleine (at 10% in DPG) 3 Evernyl 4 Dimethyl Anthranilate 4Givescone 5 Dimethyl Octenone 6 Labienoxime (1%/CQS) 6 Tangerinol 6Sandalwood GIVCO 203* 6 Florhydral 7 Allyl Amyl Glycolate 8 Romarinessential oil 8 Velvione 10 Coumarin 10 Okoumal 10 Thibetolide 10Oxyoctaline Formate 15 Isoraldeine 95 15 Gaiacwood essential oil 20Lemon essential oil California 20 Patchouli essential oil 20 AmylSalicylate 20 Benzyl Acetate 30 Geranodyle 35 Citronellol 40 LavandinGrosso essential oil 50 Alpha Hexyl Cinnamic Aldehyde 80 DihydroMyrcenol 130 Bergamote GIVCO 104* 200 Dipropylene Glycol 203 Compound offormula I 3 1000 *Fragrance Ingredients Index 2002. Givaudan S. A.

-   A) Adding 1-cyclooct-3-enylethanone to the fragrance composition    significantly increases the diffusion of the whole fragrance,    offering a better base coverage of the soap.    1-cyclooct-3-enylethanone adds a sophisticated agrestic note in the    range of armoise oil, with ozonic, cucumber undertones. It also    imparts more volume to the woody accord.-   B) Adding a mixture of 1-cyclooct-3-enylethanone,    1-cyclooct-3-enylethanone, and 1-cyclooct-3-enylethanone in the    ratio of about 60:30:10 parts by weight to the fragrance composition    imparts less sweet and more fresh, agrestic notes in the range of    armoise oil/wormwood with similar strength and enhanced diffusivity    compared to Example B.

1. A fragrance composition comprising a mixture of A) a compound offormula Ic

 and B) a compound of formula Ia, and a compound of formula Id

wherein X is carbonyl, or —(CHOH)—; and R is methyl or ethyl, or linearor branched C3 to C5 alkyl; or R is vinyl or linear or branched C3 to C5alkenyl; and R═R″═R′″ and X═X″═X′″.
 2. A fragrance applicationcomprising the fragrance composition according to claim
 1. 3. Afragrance application according to claim 2, wherein the fragranceapplication is selected from a perfume, household product, laundryproduct, body care product or cosmetic.
 4. A method of manufacturing afragrance application, comprising the step of incorporating thecomposition according to claim 1 into the fragrance application.
 5. Amethod according to claim 4, wherein the fragrance application isselected from a perfume, household product, laundry product, body careproduct or cosmetic.